Weegy: according to the reaction 2 mol of HCl (mol-weight is 35.97 g/mol) will produce one mol of sulfuric acid (mol-weight is 98.079 g/mol), 20 grams of HCl is 20g/(35.97 g/mol) = 0,5560 mol, [ so we expect half of these for sulfuric acid 0,5560/2 = 0,2780 mol of H2SO4 or 0,2780 mol *98.079 g/mol = 27.3 grams.
note: to achieve the reaction one has to use HCl in the vapor phase bubbling over sodium sulphate solution and cool the reaction continuously, this is because the tendency of the reaction is in the other way, as a matter of fact industrially sulfuric acid is dropped over sodium chloride to obtain gaseous HCl and sodium sulphate solution. ] (More)